The present work aimed to determine the effect of temperature and time during soaking of paddy rice, to obtain greater parboiled polished grain yield. For this, the central composite rotational design (CCRD) with 11 experiments was applied, considering hydration temperatures between 70 °C and 95 °C, and hydration times between 90 and 120 min. After hydration, steam cooking was carried out at a pressure of 0.151 MPa and a temperature of 110 °C for a time of 10 min and drying at a temperature of 40 °C ± 1 °C. As a result, it was obtained that both time and temperature affected the parboiled polished grain yield quadratically, since a minimum yield point was obtained. From this, the variations of both variables caused an increase in the whole polished grain yield. It was concluded that for obtaining yields between 90% - 100%, it would be necessary to use hydration time between 110 min and 115 min at temperatures between 92 and 94 °C.